哪些部分的的ARMv4 / 5/6 code将无法在ARMv7的工作吗？ [英] What parts of ARMv4/5/6 code will not work on ARMv7?

问题描述

这是我的理解是ARMv7的处理器，如在Cortex-A9，与code为老年人ARM架构的版本大多是向后兼容的。不过，我读过段错误尝试在Cortex-A8的，例如

It is my understanding that ARMv7 processors, such as the Cortex-A9, are mostly backwards-compatible with code for older ARM architecture versions. However, I've read reports of segfaults trying to run ARM9 code on a Cortex-A8, for example.

什么ARM版本的零件/ 5/6（ARM7TDMI / ARM9 / ARM11）code不会上的ARMv7处理器的工作？哪些功能或建筑特征，可能会导致专为这些版本的失败对ARMv7的程序这些旧ARM架构的版本存在？

What parts of ARMv4/5/6 (ARM7TDMI/ARM9/ARM11) code will not work on an ARMv7 processor? What features or architectural characteristics exist in these older ARM architecture versions that can cause a program built for these versions to fail on ARMv7?

推荐答案

有关申请code的主要问题是未对齐的内存访问。的ARMv4前及的ARMv4配置为从一个未对齐地址的ARMv6一个LDR负载将在所读取的数据被旋转，并且其它存储器存取充当如果至少显著2位是零。

For application code the principal problem is unaligned memory accesses. Before ARMv4 and configurable on ARMv4 to ARMv6 a LDR load from an unaligned address would in the read data being rotated, and other memory access act as if least significant 2 bits are zero.

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